The Dawn of Automated Insulin Therapy

For years, developing an “artificial pancreas” to improve the quality and convenience of diabetes was a pipe dream. The hope was to create a device which would self-monitor blood glucose and adjust insulin based on readings, activity and carbohydrate intake. After tireless research, the dream of an automated insulin delivery system became a reality. The first ever automated Hybrid Closed Loop System, the Medtronic MiniMed 670G, was approved for ages 14 and older.

The MiniMed 670G straddles the line between insulin pump and automatic delivery system. While a full closed loop system would be purely automated, this system allows the user to switch between pump and automated mode. In pump mode, the user and clinician can adjust rates and boluses. In automatic mode, the user only inputs insulin to carbohydrate ratios and insulin action time. All other features, such as target glucose and basal rates, are controlled by system parameters. While the user can switch between modes, time in the automated mode should be optimized to improve control and outcomes.

Recent studies of the MiniMed 670G resulted in significant reductions across the board in A1C, and hyper- and hypo-glycemia, . It also increased time in target blood glucose range. At the end of the three month study phase the percentage of adolescents and adults with an A1C < 7% increased by 26.6% and 20.8%, respectively. Safety was assessed in these studies as well and resulted in no cases of severe hypoglycemia or DKA. Experts believe the advantages of this system, and future systems, will eventually replace the concept of basal and bolus insulin therapy by merging basal, correction and meal dosing together through automation.

To allow the device to accurately manage dose adjustments, a new and purportedly more accurate continuous glucose monitor was created. However, the system can operate with current continuous glucose monitors on the market. The MiniMed 670G is generally affordable as it is covered by most insurances for new users or for users with a device five years or older. With the system now available to order and it’s glucose monitor set to release this fall, the importance of education on these devices is brought forth.

Understandably, the concepts of this new system create quite a learning curve for clinicians and users alike. To help clinicians better conceptualize these products, the CARE acronym can be used to decipher important characteristics. First is “CALCULATE”, to determine which dosing parameters are calculated or fixed by the system versus which are modifiable by the user. Second is “ADJUST”, how do users adjust the system based on hyper- and hypo- glycemia? Third is “REVERT”, to make sure users optimize time spent in automatic mode, and know when to revert to the pump mode, such as during illness. Last is “EDUCATION”, to make sure the clinician and user know what resources are available and how to access them. Combining both the CARE acronym with device manuals and manufacture guidance is important to help clinicians provide proper care and education to new users.

The development of the Medtronic 670G and future automated insulin delivery systems make for an exciting time in diabetes management. With this new technology on the horizon, now is the time for clinicians to begin to conceptualize the operation of these devices to better provide quality care to diabetic patients.